Furnace-grate



1. A. PACKARD.

FURNACE GRATE.

APPLICATION FILED OCTI 22. I917. 1,344, 144:. Patented June 22, 1920.

4 SHEET S-SHhE] 1 J. A. PACKARD.

FURNACE GRATE.

APPLICATION FILED OCT. 22, 1917.

Patented June 22, 1929,

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FURNACE GRATE.

APPUCATION FILED OCT. 22, I917.

Patented June 22, 1920.

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J. A. PACKARD.

FURNACE GRATE.

APPLICATION FILED OCT. 22. I917.

Patented June 22, 1920.

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A TTORNEY UNITED STATEVIIS'VV'PTATENT OFFICE.

JAMES A. PACKARD, or MILWAUKE WISCONSIN, AssIGNoR TO PACKARD sroxnn CORPORATION. or AMERICA, or MILWAUKEE, WISCONSIN, A CORPORATION or WISCONSIN.

FITRNACE-GRATE.

' Patented June 22,1920.

Application fi1ed.0ctober 22, 1917. Serial No. 197,868.

To all whom it may concern Be it known that 1, JAMES A. PACKARD, a citizen ofthe United States, and resident of Milwaukee, Milwaukee county, W1scons1n, have invented new and useful Improve ments in Furnace-Grates, of which the following is a description, reference being had to the accompanying drawings, which are a part of this specification. I

This invention has for its object to provide a furnace grate of the inclined type having means for advancing the fuel from one step to another for progressively stok- Another object of the invention is to provide the grate bars of the furnace with an air passage receiving compressed. air and ejecting it through suitable openings into the bed of burning fuel. 7

Another object for the invention is to provide means for. varying the inclination of the grate.

Another object for the invention is to so construct the grate that parts may be re moved for repair without interrupting the operation of the furnace.

Another object for the invention is to provide the grate with means for crushing the clinkers before discharging. them into the ash pit. 'Another object for theinvention is to perfect details of construction of the various parts of grates of this type. V

WVith the above andother objects in view, the invention consists in the grate as herein claimed and all-equivalents. j

Referring to theaccompanying drawings in which like characters of reference indicate the same parts in the different views:

Figurel is alongitudinal sectional view of a grate constructed in accordance with this invention, the parts being in their normal positions for the operation of the furnace; i I

Fig. 2 is a similar view thereof with the parts in position for advancing the fuel along the grate;

Fig. 3 is a plan view with dotted lines 1f1 and 2-2 indicating the sectional planes of Figs. 1 and2, respectively; I

Fig. 4 is a sectional perspective view showing an end of a grate bar and the fitting therefor Fig. 5 is a sectional view through one of the headers showing the valve for controlling the admission of air to the lowermost grate bar;

Fig. 6 is a detail view showing an intermediate fitting for a grate bar;

Figs. 7 and 8 are sectional views showing end fittings for a grate bar;

Fig. 9 is a perspective view of the detachable connection with the power operating means; and, i

Fig. 10 is a plan view of the hearth or frame around the lower part of the grate.

In these drawings 10 indicates arectangular base preferably set below the floor line and constituting an ash pit, while 11 is the furnacefront bolted thereto and connected with a pivot shaft 12 which is mounted on a pair of A-shaped upright frames 13. The upper portion of the furnace'front 11 constitutes an inclined feedv hopper 14 into which fuel is fed in any suitable manner from above. A stepped pusher slide 15 is reciprocated along the bottom of the inclined feed hopper 14 by having link connection with bell cranks 16, which in turn are connected byv links 17 with arms 18 on a rock shaft 19. The rock shaft 19 is jo'urnaled in bearing brackets on the furnace front and has an arm 20 having detachable connection with. an arm 21 of an eccentric strap 22 surrounding an eccentric 23 on a drive shaft 24. The drive shaft 24 isjournaled in suitable bearing brackets on the furnace front and preferably extends the full length of the battery of furnaces and is driven in any suitable manner. The arm 20 is made detachable from the arm 21 in the mannerv shown in detail in Fig. 9. The arm 20 has a headed pin 25 to fit in a groove 26 of the arm 21, and a sliding slotted latch plate 27 on the arm 21 confines it to the notch. When the latch plate is lifted, however, the pin may be removed from the notch and thus disconnect the parts so that the shaft 19 is not rocked by the rotations of the drive shaft 24.

Leading from the lower end of the feed hopper or chute 14 is a series of horizontal hollow grate bars 28 forming an inclined bank or support for the fuel. This inclined series of grate bars is pivotally suspended from the shaft 12 so as to swing to vary the inclination thereof more or less. The grate bars are tubular with longitudinal slots 29 at their front beveled edges and their ends slidably fit in L-shaped end pipe fittings 30' or 31, and T-shaped middle fittings .32. The pipe fittings 30, 31 and 32 have downwardly projecting stems fitting inopenings along the steps of inclined headers 33 of which there are three pivotally mounted on the shaft 12. The headers are hollow and are supplied with compressed air by having connection with a compressed air supply pipe 34. The connection between the air pipe 34 and the headers 33 is formed by telescoping sections curved to permit of the swinging movements of the grate, and valves, 35 controlled by rods 36 extending through the furnace front govern the flow of air into the headers.

The air from the headers is communicated to the grate bars 28 through the various fittings which have slots 29 to discharge it into the fuel as with the slots of the grate bars. At one end of the grate the fittings 3O establish communication through their stems from the header to the ends of the grate bars. The middle fittings do likewise but are preferably closed by a partition 37' against communication with the portions of the grate bar supplied by the fittings 30. The fittings 31 are preferably closed by partition 38 against communication with the grate bars except for the lowermost grate bar where the fitting 31" is without such partition and is the Only one to conduct the air from the header at this end of the grate. This lowermost grate bar, furthermore, re-

ceives the air from this header only and the flow. of air to it is controlled by a valve 39 operated by a notched handle 40 passing through the furnace front.

There is suificient space between the successive grate bars to permit feeding slides 4-1 to closely fit therebetween and said slides at their ends fit in grooves 42 in the headers and are capable of sliding from'an inner position, shown in Fig. 1, to an outer position, shown in Fig. 2, and in sodoing force the fuel off of each gratebar upon the slides below to be deposited on'the lower grate bars when the slides are retracted again to their inner position.

At its ends each feeding slide has connection with the inclined connector 43 which has racks 44 projecting therefrom and mesh; ing with segmental gears 45 keyed on shafts 46 which are journaled in brackets project ing from the headers. A link47 connects an arm on one of the upper segmental gears 45 with an arm on one of the lower segmental gears 45, so that both shafts 46 move together and a. link 48 connects the last men tioned arm with an arm 49 on rock shaft 19. The rocking movements of shaft 19 caused by its eccentric connection with the drive shaft 24, produces an oscillation of the segmental gears 45 to move the feeding slides 41 in and out and it is preferred to have the two eccentrics for each furnace set diametrically opposite so that the feeding slides on one side of the furnace are in their outer position while the slides on the other side are in their inner positiomas shown 111 Fig. 3.

A frame 50, shown in detail in Fig. 10, connects the lower ends of the headers and forms a hearth about the lower end of the grate with stepped ledges forming guide supports for a pair of slides 51 and 52. The slide 51 fits between the slide 52 and the lowermost grate bar. These slides have their front edges serrated to form teeth for crushing clinkersagainst the hearth frame 50, and the lower slide 52 has transverse slots through whichthe ashes may pass to the ash pit below. The upper slide 51 is given movement at aspeed faster than the feeding slides 41 by having link connections53 with crank arms 54 on pinions rotatably mounted on the headers and meshing with the teeth of segmental gear-s45. The size of the pinions 55 is such that the slide 51 makes a complete reciprocation with each movement of the feeding slides in either direction. Theslide 52 'is operated by means of a lever 56 on the furnace front, the connection between the slide and the lever consisting of a connecting rod 57. The lever is preferably provided "with a toothed quadrant by which'it may beheld in its va rious adjustments tohold the slide 52'with its front edge spaced from the hearth frame 50 to a perdetermined degree.

The headers 33 have segmental racks 58 mounted on their lower ends, the curvature of said racks being from the pivotal shaft 12 as a center. The racks 58 mesh with pinions 59 on a shaft 60 journaled across the base 10, and the worm wheel 61 on said shaft is engaged by a worm 62 on a shaft which passes through the furnace front and is turned by means of a crank'handle (54 on its end. f I V In operation the fuel'is fed into the "receiving trough or hopper 14 by any suitable means and is worked along the'incline by the reciprocation of the slide 15 untilits discharge upon'the grate bars. The blast of air delivered horizontally from each of the grate bars and their fittings, as controlled by the, position of valve 35', maintains the fuel in the state of incandescence'to which it has been raised by the heat of the furnace by the time it reaches the grate bars, and the slowly reciprocating slides 41 gently shift the burning fuel. from one grate bar to the next until it reaches the slide 52. Here the more rapidly reciprocating slide 51' works the ash through the slotsbof the slide 52 and over the serrated outer edge thereof, and such clinkers as may havebeen formed of a size to prevent their passing through the space between the slide 52 and the hearth frame 50 will. be crushed by the slide 51 39 permits of more efficient regulation.

hen it is observed that the fuel is reduced to ash before it reaches the hearth, the flow of air to the lowermost grate bar may be stoppedby closing the valve 39, thus avoiding the introduction of air that does not pass-through burning fuel. When, however, it is found that the fuelreaches the hearth while it is still burning, air is admitted to the lowermost grate bar by opening the valve 39 more or less according to the state of the fuel when it reaches the hearth.

The inclination of the grate as a whole may be varied to obtain the desired speed of travel of the fuel over-it or to accommodate it to different fuels by turning the crank 64 and thereby turning the shaft 60 and causing the pinions and segmental racks to swing the grate on its pivotal connection with shaft 12. This is accomplished without impairing its operative connection. The,

shaft 19 is provided with a socket 67 to receive a suitable handle for giving hand operation to the feeding slides whendesired.

The grate bars 28, as previously stated, have a sliding fit at their ends within their fittings so that they may be removed by sliding them rearwardly out of such fittings. The fittings are provided with turn buttons 65, as seen in Fig. 4, to engage cam shaped projections 66 on the back of the grate bars for holding the grate bars firmly in place during operation. Should one-of the grate bars burn out, or if for any other reason it should be desired to removeit, the furnace section may be thrown out of operation by closing the valve 35 and disconnecting the arm 21, and the repair man may enter through an opening in the furnace front and, by turning the buttons 65, the defective grate bar may be drawn rearwardly out of its fittings and replaced with another. Should one of the fittings become injured, it may be removed by forcing it upwardly out of the socket of the header, and the new one may be readily put in its place.

I desire it to be understood that this invention is not limited to any specific form or arrangement of parts except in so far as such. limitations are specified in the claims. lVhat I claim as new and desire to secure by Letters Patent is:

1. An inclined stepped grate pivotally suspended at its upper end, segmental racks at its lower end, a shaft having pinions meshing with the segmental racks, and a worm driving means for said shaft for swinging the grate on its to change its inclination.

2. A pivotally supported inclined stepped grate formed of hollow slotted grate bars, means for swinging the grate as a unit on its pivotal support to change its inclination, and 'means for supplying compressed air to the hollow grate bars in the different positions of the grate. 3. An inclinedvstepped grate comprising hollow headers, hollow fittings removably mounted thereon, slotted hollow grate bars slidably connected to said fittings and removable therefrom toward the rear of the grate and receiving'air from the sectional headers through said fittings, and means for locking the grate bars to said fittings.

4; In an inclined grate, grate bars spaced apart, feeding slides fitting between the grate bars and moving over the fuel supporting surfaces thereof, a bar to which the feeding slides are connected, racks on said bar, gears meshing with said racks and connected together, and means for oscillating the gears to reciprocate the feeding slides.

5. An inclined stepped grate, comprising spaced grate bars,'feeding slides working therebetween, a hearth frame around the lowermost grate bar, an adjustable slide therein,andaclinker crushing slide between {)he adjustable slide and the lowermost grate '6. An inclined stepped grate, comprising spaced grate bars, feeding slides working therebetween, a bar to which the feeding slides are connected, racks on said bar, suitably operated gears meshing with the racks, a hearth frame around the lowermost grate bar, an adjustable slide therein, a clinker crushing slide between the adjustable slide and the lowermost grate bar, and a pinion meshing with one of the gears and having a crank connected with the clinker crushpivotal support ing slide.

7. An inclined stepped grate, comprising headers, transversely extending slotted tubular grate bars connecting the headers, the lowermost grate bar communicating with one'header and the other grate bars communicating with the other headers, and valve-controlled means for supplying compressed air to the headers.

8. In a furnace, the combination of a pivotally supported inclined stepped grate formed of hollow slotted grate bars, means for adjusting the inclination of said grate on its pivotal support, and means for supplying compressed air to said grate bars in its different adjusted positions including air conduits connected to and movable with said grate bars.

9. In a furnace, the combination of a pivotally supported inclined stepped grate formed of hollow slotted grate bars, means for adjusting the inclination of said grate onits pivotal support, means for supplying compressed air to said grate bars in its different adjusted positions including air conduits connected to and movable with said grate bars feeding slides carried by said grate and movable between-the grate bars, and means for reciprocating the feeding slides in any adjusted position of the grate bars.

In afurnace, the combination of supporting means, headers pivotally mounted on said supporting means, hollow slotted gratebars secured to said headers instepped formation and movable therewith, feed slides guided on said headers between said grate bars, means for moving and adjustably securing said headers and grate bars at different inclinations means for reciproe eating said feed slides, and means forconductin compressed air to the headers in the di erent positions of the grate. 1

11. In a furnace, an inclined stepped grate 

